-#define CSIZE 0x00000300 /* character size mask */
-#define CS5 0x00000000 /* 5 bits (pseudo) */
-#define CS6 0x00000100 /* 6 bits */
-#define CS7 0x00000200 /* 7 bits */
-#define CS8 0x00000300 /* 8 bits */
-#define CSTOPB 0x00000400 /* send 2 stop bits */
-#define CREAD 0x00000800 /* enable receiver */
-#define PARENB 0x00001000 /* parity enable */
-#define PARODD 0x00002000 /* odd parity, else even */
-#define HUPCL 0x00004000 /* hang up on last close */
-#define CLOCAL 0x00008000 /* ignore modem status lines */
-#ifndef _POSIX_C_SOURCE
-#define CCTS_OFLOW 0x00010000 /* CTS flow control of output */
-#define CRTSCTS (CCTS_OFLOW | CRTS_IFLOW)
-#define CRTS_IFLOW 0x00020000 /* RTS flow control of input */
-#define CDTR_IFLOW 0x00040000 /* DTR flow control of input */
-#define CDSR_OFLOW 0x00080000 /* DSR flow control of output */
-#define CCAR_OFLOW 0x00100000 /* DCD flow control of output */
-#define MDMBUF 0x00100000 /* old name for CCAR_OFLOW */
+#define CSIZE 0x00000300 /* character size mask */
+#define CS5 0x00000000 /* 5 bits (pseudo) */
+#define CS6 0x00000100 /* 6 bits */
+#define CS7 0x00000200 /* 7 bits */
+#define CS8 0x00000300 /* 8 bits */
+#define CSTOPB 0x00000400 /* send 2 stop bits */
+#define CREAD 0x00000800 /* enable receiver */
+#define PARENB 0x00001000 /* parity enable */
+#define PARODD 0x00002000 /* odd parity, else even */
+#define HUPCL 0x00004000 /* hang up on last close */
+#define CLOCAL 0x00008000 /* ignore modem status lines */
+#if !defined(_POSIX_C_SOURCE) || defined(_DARWIN_C_SOURCE)
+#define CCTS_OFLOW 0x00010000 /* CTS flow control of output */
+#define CRTSCTS (CCTS_OFLOW | CRTS_IFLOW)
+#define CRTS_IFLOW 0x00020000 /* RTS flow control of input */
+#define CDTR_IFLOW 0x00040000 /* DTR flow control of input */
+#define CDSR_OFLOW 0x00080000 /* DSR flow control of output */
+#define CCAR_OFLOW 0x00100000 /* DCD flow control of output */
+#define MDMBUF 0x00100000 /* old name for CCAR_OFLOW */